One county identified ‘norovirus’ likely to be the reason in a warning issued to hikers visiting Havasupai, a destination that attracts thousands of tourists annually. Some afflicted visitors were too weak to hike out of the remote campsite at the bottom of the canyon, which is inaccessible by car and required evacuation by helicopter.

One of the affected campers, Madelyn Melchiors, 32, described her harrowing experience as she fell severely ill, vomiting and suffering from a fever for days after setting up camp on the Havasupai reservation. Despite her weakened state, Melchiors managed to hike 10 miles out of the site but had to use a mule to carry her camping gear.

“I said, ‘If someone can just pack out my 30-pound pack, I think I can just limp along,’” said Melchiors, an experienced backpacker. “I slept 16 hours and drank a bunch of electrolytes [afterward]. I’m still not normal, but I will be OK. I’m grateful for that.”

Federal Indian Health Service environmental health officers were dispatched to Havasupai to investigate the outbreak and implement measures to prevent further spread. While the exact source of the outbreak remains unclear, Melchiors mentioned she drank from a spring that had been tested and approved as potable. She also used a water filter to screen out bacteria and protozoa, though these common gravity-fed filters do not typically remove viruses.

The Havasupai Tribe Tourism Office confirmed that water from the local spring used by visitors had been tested last week and deemed safe for consumption. Meanwhile, an Indian Health Service-run clinic on the reservation is treating ill patients and visitors.

“Our priority is the health and well-being of the Havasupai residents and visitors, and we are working closely with local health authorities and other partners to manage this situation effectively,” the agency said.

Coconino County health officials issued a warning to visitors after a group of hikers reported gastrointestinal illness symptoms: “Watch for early symptoms of norovirus, such as stomach pain and nausea, before the trip. Norovirus spreads easily on camping trips, especially when clean water supplies can be limited and handwashing facilities may be nonexistent. Isolate people who are sick from other campers,” the county advised.

In recent days, many visitors have taken to social media to share their experiences, detailing their gastrointestinal struggles and reporting sightings of toilet paper, plastic bottles, and other trash littering the trails.

What is Norovirus?

According to the Centers for Disease Control and Prevention, norovirus is a type of contagious virus that results in vomiting and diarrhea. Although it is also called'stomach flu’ or stomach bug’, the norovirus illness is not related to the flu. Norovirus causes acute gastroenteritis, an inflammation of the stomach or intestines. It may take 1 to 3 days for a norovirus-infected person to get better, but they can still spread the virus a few days after.

Diarrhea, vomiting, nausea, and stomach pain are the most common symptoms of norovirus. Some people may also experience fever, headache, and body aches.

Norovirus illness leads to dehydration, and so people may also experience decreased urination, dry mouth and throat, feeling dizzy when standing up, crying with few or no tears, and unusual sleepiness or fussiness.

Norovirus symptoms usually start to appear within 12 to 48 hours of exposure to the virus.